Ezekiel mentioned several times that "the spirit of the living creatures was in the wheels". That doesn't sound like he thought he was seeing some type of alien craft, but rather a living being. He called them Cherubims. In Eze. 10:20, he even said he knew they were Cherubims. He doesn't seem at all baffled about what he saw or what the "living creatures" were.

Seems like many people today are confused as to the identity of these beings, but Ezekiel was not. A lot of "UFO" accounts make mention of the fact that people feel like the "UFO" is watching them or trying to communicate with them. That would seem to support what Ezekiel said with regard to the "UFO" craft itself being a living creature.

Eze 1:20 Whithersoever the spirit was to go, they went, thither was their spirit to go; and the wheels were lifted up over against them: for the spirit of the living creature was in the wheels.

Eze 10:17 When they stood, these stood; and when they were lifted up, these lifted up themselves also: for the spirit of the living creature was in them.

Eze 10:20 This is the living creature that I saw under the God of Israel by the river of Chebar; and I knew that they were the cherubims.